Pages

Wednesday, 21 May 2014

A visit to the Heping cement CO2 capture demonstration project in Taiwan

Update (25.5.2014): Since I have arrived home and am no longer relying on dodgy hotel internet, I have been able to upload a video of the plant I took while I was there. The video gives a better idea of the scale of the factory that the picture cannot, simply because you can't fit the whole plant into the shot. The video is on YouTube, but I've embedded it here:

Also, if you want an aerial view of the plant, you can find it on google maps here.

The introduction to this post is that I'm writing it from the luxury of a rather swanky 5-star hotel in Taipei.

Taiwan is not in a great position with respect to energy. They have few natural resources of their own to utilise - only a few small natural gas fields in the north of the country. Nuclear is a troublesome subject for such an earthquake-prone island, especially after Fukushima. While you might think that such a mountainous island would be a good site for renewables, the regular earthquakes, landslides and typhoons means that maintaining a large number of wind turbines will also prove difficult. As a result, the majority of Taiwan's electricity comes from coal, most of which is imported from Indonesia.

In addition, there is a lot of heavy industry in Taiwan's economy, and especially cement manufacture, which releases a lot of CO2.

Given their vulnerable position with respect to typhoon activity (Taiwan is typically hit by 3 typhoons a year on average), the Taiwan government is very concerned about climate change, and for the reasons outlined above the principal component of its emissions reduction plan is carbon capture and sequestration (CCS). So myself and a number of "experts" in various CCS-related topics have been spending the week discussing CCS with Taiwan's EPA (Environmental Protection Agency) and ITRI (Industry Technology Research Institute) agencies. I was there to discuss issues of injection-induced seismicity, and potential implications for CO2 leakage, which has proved a major public concern as demo injection projects have been proposed.

However, the point of this post is not to discuss induced seismicity. As part of the trip we were given a tour of a cement factory in Heping, Eastern Taiwan. This plant has installed a CO2 capture pilot plant, which removes CO2 from the exhaust gases that come from the factory. I thought I'd share some photos from the tour, as well as some thoughts on my experience (because it was quite some experience).

The cement factory is absolutely enormous. We could see stacks looming over the jungle as we arrived at the train station:

The scale of the factory really has to be seen to be believed. The photos simply don't do it justice - this is a huge construction:

The CO2 capture plant is only a demo stage. It captures 1 ton of CO2 per hour, from a 1.9MW section of the plant (the whole plant is 300MW, so it really is only a small part of the whole plant). The capture plant is quite a large structure in and of itself, but completely dwarfed by the main factory.

The capture plant works using the process of calcination. You start with calcium carbonate, CaCO3 (which is limestone). When heated, this decomposes to calcium oxide, CaO (lime) and CO2. The released CO2 is 99.9% pure, and can be captured and compressed for shipment. The reaction is reversible, so the CaO is reacted with the flue gas, taking in the CO2 to form CaCO3.

So you have a cyclical process - CO2 is separated from the exhaust gases by reaction with CaO in a fluidised bed. The CaCO3 is then moved to a rotating kiln, and heated to give off the pure CO2 as a separate stream. The major cost is in the re-heating, which means that the process costs $40 per ton of CO2.

The captured CO2 is currently being used to enhance the growth of micro-algae that are being used for bio-diesel. The were a few experimental tanks next to the capture plant.

The last one with the disco lights is an experiment to see whether different light wavelengths improve the growth-rates of the algae.

The current plant captures 1 ton of CO2 per hour, which is pretty small beer on the grand scheme of things. The Taiwan government plans to have a larger scale project up and running by 2020. Where this demo is working on a 1.9MW plant, they want to scale this up to a 300MW plant. The hope is that scaling up and improving efficiency will reduce costs to $20 per ton of CO2. The full scale plant will produce far too much CO2 to be used for algae and biofuels.

Instead, the intention is to use as much as possible for enhanced gas recovery (EGR) in the small natural gas fields in northwest Taiwan, and to store whatever remains in deep saline aquifers off the west coast - which is where my seismological knowledge was required to ensure that storage could be achieved safely.

Taiwan has a number of small natural gas fields - which have stored gas safely despite all of the seismicity (Taiwan experiences 20,000 detected earthquakes per year). Taiwan also operates natural gas storage projects - injecting natural gas into saline aquifers for storage, to be removed for use at later dates (usually in the winter when gas is more expensive). If these natural gas fields and storage sites can maintain storage integrity, there is no reason to think that CO2 could not be stored safely. However, as with all such projects, rigorous site characterisation and geomechanical modelling should be conducted before injection starts, and injection should be monitored throughout with a range of geophysical techniques.

I'll close, however, not with geophysics but with some wider thoughts. Much like when I once visited Beijing, this site really shows the scale of the issue we face if we are to reduce human CO2 emissions to a sustainable rate. This cement plant is absolutely, mind-blowingly, huge! It's churning through coal and calcium carbonate, and burping out CO2, at an incredible rate. The amount of energy this plant must consume is huge.

Much of the world's CO2 emissions are forecast to come from countries like Taiwan that are looking to grow their economies substantially, powered mostly by coal. There's simply no way that a plant like the one we visited today can be powered by renewable energy sources. Not a chance. Yet plants like this are absolutely vital to Taiwanese economic development - this is the major employer in the district. Even if we in the west make every effort to move to renewable energy sources, I don't see these as being viable in any significant way for some of these developing nations. Yet when it comes to CO2, the world doesn't care what country emitted it.

It is rather fortunate that my visit today coincided with the release of the House of Commons Energy and Climate Change Select Committee report on CCS, which has urged for the technology to be fast tracked. Without CCS, I don't see how we can otherwise deal with this issue - maintaining economic growth in developing economies while reducing emissions. It is reassuring to see that the Taiwanese (or the government and academia at least) appear to be as keen for CCS as our Select Committee is.

11 comments:

Hi JV, I find this a very interesting blog. I cannot see how CCS can be economically viable. Those countries that use this technology, if it can be developed, will find their industry undercut by those nations that do not use it. In fact the whole idea of all industrial nations agreeing to significant binding cuts in CO2 emissions seems to be a non-starter. Cuts by the "developed" nations alone will simply not achieve the CO2 reductions needed to prevent levels from continuing to increase. I am surprised that you are still convinced that these cuts are necessary in the light of increasing evidence that climate sensitivity to CO2 is much lower than originally predicted by the climate models. Surely the 17 years without any significant warming must give you pause for thought. I realise that it is difficult for you to take a sceptic view when your work, to a significant degree, depends upon the need for CCS.

In terms of economic viability, in most studies CCS generally comes in cheaper in terms of £ per ton of CO2 mitigated than other technologies like offshore wind and large-scale solar PV.

I agree that climate sensitivity might be more uncertain than it is sometimes portrayed. However, I don't think that uncertainty means we should continue to increase CO2 emissions IF there are ways available to us that can mitigate them.

The question is whether the technologies required to mitigate emissions really can be deployed at the scales required, at a low enough price that our way of life is not significantly impacted. I don't think anyone yet knows the answer to this question - I'm not going to put my faith in the few desktop studies and computer-based economic simulations that have been done. This is something that we'll find out "experimentally" in the next 50 years or so: can we really run a "western-level" economy without significant CO2 emissions?

I agree that the problem of "free-riding" is a major one for any kind of effort to reduce CO2 emissions. If most countries agree to some sort of target, those that stay outside of it will be at a competitive advantage. As a result, heavy-emitting industry will tend to re-locate to those countries outside the agreement, where they can continue to emit their CO2 with impunity.

However, from what I saw during my week in Taiwan, talking to the people inside their government and industrial organisations, is that they are taking CO2 emissions seriously, and want to put measures in place to reduce them. The were also delegates from other SE Asian countries - Thailand, Philippines, Japan etc, who had similar views.

I'll admit, this surprised me - I was expecting lip-service, but they seemed genuinely keen to move forward on CCS quickly - hence they have a working capture demo plant up and running while we in the UK are still in the design phase!

I meant to add that the geophysical methods we are developing here at Bristol are equally applicable to conventional oil and gas, to unconventional gas, and to geothermal. We have no particular financial incentive in CCS, so I am not particularly motivated to see it succeed.

Personally I think that having CCS will help us reduce CO2 emissions more easily than if we didn't have it. But I'm not sure how much effort we'll ever really be prepared to make to do so (for the reasons above). I've gone through varying degrees of optimism and pessimism about the future for CCS. When I first started (2004-5), I thought we'd have operational plants by 2010-ish. By 2010, it seemed like a dead duck. Now things seem to be moving forward again.

However, if CCS doesn't ever get beyond the research phase, well, I have plenty of other people keen for my services.

Thanks for the reply. My opinion is that the political agreement will not be possible, as no government can agree to something that will make their own people worse off. The previous Kyoto agreement gave huge concessions to developing nations such as China and India. The USA, quite rightly, refused to sign up to it, though some states tried to act unilaterally. Any future agreement must include all industrial nations on a level playing field. That is why it won't happen.

My view is that the real understanding of the climate is poor, and the current pause is reinforcing that. Politicians are picking up on that and so will be less willing to take tough unpopular decisions.

Maybe the Taiwanese are hoping to sell their CCS technology to the world, but unless there is a world-wide agreement it will be a tough job. The UK has found it very difficult to find anybody to invest even in a pilot plant with government subsidy.